DE112021005640T5 - Additive manufactured object, method of manufacturing an additive manufactured object and additive manufacturing apparatus - Google Patents

Abstract

An object made by additive manufacturing is a stack comprising a first metal layer (230) formed from a first metallic material and a second metal layer (240) comprising second point grains (241) formed from a second metallic material are included. The object produced by additive manufacturing comprises an intermediate layer (250) between the first metal layer (230) and the second metal layer (240). The intermediate layer (250) comprises a first structural part (251) which is a structure formed from the first metallic material and a second structural part (252) which is a structure formed from the second metallic material. The first structural member (251) and the second structural member (252) interlock in a unitary structure (253), and an arrangement of the unitary structures (253) disposed in the intermediate layer (250) has translational symmetry in a plane that is perpendicular to a stacking direction of the first metal layer (230) and the second metal layer (240). The intermediate layer (250) comprises an intermetallic compound layer, which comprises an intermetallic compound, at a connecting surface between the first structural part (251) and the second structural part (252).

Description

Area

The present disclosure relates to an additive manufactured object that is additively manufactured with different types of metallic materials. The present disclosure also relates to a method of manufacturing the additive manufactured object and an additive manufacturing apparatus.

background

An additive manufacturing method that uses a technique for manufacturing a three-dimensional object called additive manufacturing (AM) is known to combine different types of metal into an additively manufactured object, i. H. into a three-dimensional object. In the process of additive manufacturing, a molten pool is formed on a first metal layer of a first metal, generally with a laser or an energy beam, such as an electron beam. A second metal, different from the first metal, is introduced into the molten pool in the form of a filament, then melts and solidifies to form a second layer of metal. An object produced by additive manufacturing is hereby obtained. However, depending on the combination of the first metal and the second metal, a brittle intermetallic compound may form at a junction interface between the first metal layer and the second metal layer, resulting in a reduced bond strength at the junction interface.

In an additive manufacturing method disclosed in Patent Literature 1, with phase diagrams for reference, a first metal and a second metal are preselected as a combination which does not form an intermetallic compound but forms a solid solution and one made by additive manufacturing object is formed. Further, in the additive manufacturing method described in Patent Literature 1, coupling parts are formed at three or more positions which are at an interface between a first metal layer formed of the first metal and a second metal layer formed of the second metal. are not on the same straight line to mechanically couple the first metal layer and the second metal layer. Each of the coupling parts includes a first component that has a T-shaped portion with a stacking direction and is formed of the first metal, and a second component that surrounds the first component and is formed of the second metal.

citation list

patent literature

Patent Literature 1: Japanese Patent Application, Publication No 2020-41201

short description

Technical problems

However, in the technique of Patent Literature 1 in which the combination that forms the mixed crystal at the interface between the first metal and the second metal is preselected, the selection can be made only for binary combinations. In addition, the combination that forms the solid solution is actually limited to pure metals. Pure metals are seldom intended as a combination of practical metals which is widely used, and a binary alloy or higher alloy is common in practical use. Therefore, a problem of the technique described in Patent Literature 1 is low versatility. In addition, since in the technique described in Patent Literature 1, the coupling parts are not provided on the same straight line at the at least three positions on the interface between the first and second metal layers, i. H. on the first metal layer, when a force acts in a direction separating the first metal layer and the second metal layer, the stress concentrates on the coupling parts. Therefore, another problem is that a uniform bond strength across the interface between the first and second metal layers is not ensured.

The present disclosure was made in view of the above, and an object of the present disclosure is to obtain an additive manufactured object that ensures uniform bonding strength at an interface between a first metal layer and a second metal layer without sacrificing relation to be limited to a combination of a first metal for the first metal layer and a second metal for the second metal layer, as is conventional.

solving the problems

In order to solve the above problems and achieve the object, according to the present disclosure, an additive manufactured object is a stack including a first metal layer formed of a first metal material and a second metal layer comprising second point grains formed of a second metallic material. The additive manufactured object includes an intermediate layer between the first metal layer and the second metal layer. The intermediate layer includes a first structural part, which is a structure formed from the first metallic material, and a second structural part, which is a structure formed from the second metallic material. The first structural part and the second structural part interlock in each of a plurality of unit structures, and an arrangement of the unit structures arranged in the intermediate layer has translational symmetry in a plane perpendicular to a stacking direction of the first metal layer and the second metal layer. The intermediate layer comprises an intermetallic compound layer comprising an intermetallic compound at a connection surface between the first structural part and the second structural part.

Advantageous Effects of the Invention

The additive manufacturing object according to the present disclosure has the effects over a conventional one that it is not limited in a combination of a first metal for the first metal layer and a second metal for the second metal layer and that a uniform bond strength at an interface between the first middle class and the second middle class is guaranteed.

character list

• 1 12 is a diagram schematically showing an example configuration of an additive manufacturing apparatus according to a first embodiment.
• 2 12 is a block diagram showing a first example of a hardware configuration for a control unit of the additive manufacturing apparatus according to the first embodiment.
• 3 12 is a block diagram showing a second example of the hardware configuration for the control unit of the additive manufacturing apparatus according to the first embodiment.
• 4 14 is an enlarged view schematically showing an example of an object formed by line grains.
• 5 12 is an enlarged view schematically showing an example of an object formed by point grains.
• 6 14 is a cross-sectional view showing an example configuration of an additive manufactured object according to the first embodiment.
• 7 14 is a partial perspective view showing the exemplary configuration of the additive manufactured object according to the first embodiment.
• 8th 14 is a partial cross-sectional view showing the exemplary configuration of the additive manufactured object according to the first embodiment.
• 9 14 is a diagram showing an example configuration of an intermediate layer of the additive manufactured object according to the first embodiment.
• 10 14 is a diagram showing another example configuration for the intermediate layer of the additive manufactured object according to the first embodiment.
• 11 14 is a diagram schematically showing an example of a joint surface between a first point grain and a second point grain in the additive manufactured object according to the first embodiment.
• 12 14 is a diagram showing an example of a state of components at the joint surface between the first point grain and the second point grain in the additive manufactured object according to the first embodiment.
• 13 is a phase diagram of Al-Fe.
• 14 14 is a cross-sectional view schematically showing a process example of a method of manufacturing the additive manufactured object according to the first embodiment.
• 15 14 is a cross-sectional view schematically showing the process example of the method of manufacturing the additive manufactured object according to the first embodiment.
• 16 14 is a cross-sectional view schematically showing the process example of the method of manufacturing the additive manufactured object according to the first embodiment.
• 17 14 is a cross-sectional view schematically showing the process example of the method of manufacturing the additive manufactured object according to the first embodiment.
• 18 Fig. 12 is a cross-sectional view showing the process example of the method of Finish ens of the object produced by additive manufacturing according to the first embodiment schematically shows.
• 19 Fig. 12 is a diagram schematically showing an example of a joint surface between a first point grain and a second point grain in a prior art additive manufactured object.
• 20 Fig. 12 is a diagram showing an example of a state of components at the connection surface between the first point grain and the second point grain according to the prior art.
• 21 14 is a partial cross-sectional view showing an example configuration of an additive manufactured object according to a second embodiment.
• 22 14 is a diagram showing an example of how dot grains are arranged in an additive manufactured object according to a third embodiment.
• 23 14 is a cross-sectional view showing an example configuration of an additive manufactured object according to a fourth embodiment.
• 24 14 is a perspective view schematically showing a process example of a method of manufacturing the additive manufactured object according to the fourth embodiment.
• 25 14 is a perspective view schematically showing the process example of the method of manufacturing the additive manufactured object according to the fourth embodiment.
• 26 14 is a perspective view schematically showing the process example of the method of manufacturing the additive manufactured object according to the fourth embodiment.
• 27 14 is a perspective view schematically showing the process example of the method of manufacturing the additive manufactured object according to the fourth embodiment.
• 28 14 is a perspective view schematically showing the process example of the method of manufacturing the additive manufactured object according to the fourth embodiment.
• 29 14 is a perspective view schematically showing the process example of the method of manufacturing the additive manufactured object according to the fourth embodiment.
• 30 14 is a perspective view schematically showing the process example of the method of manufacturing the additive manufactured object according to the fourth embodiment.

Description of Embodiments

Referring to the drawings, a detailed description of additive manufactured objects, methods of manufacturing the additive manufactured objects, and an additive manufacturing apparatus according to embodiments of the present disclosure is provided below.

First embodiment.

1 12 is a diagram schematically showing an example configuration of an additive manufacturing apparatus according to a first embodiment. An additive manufacturing apparatus 1 is a direct energy deposition (DED) additive manufacturing apparatus which forms an additive manufactured object 220, which is a three-dimensional object, by repeating an additive process of adding an irradiation molten material to a target addition surface 110 of a workpiece 100 . An X-axis and a Y-axis are two axes orthogonal to each other in a plane surface of a base member 12 where the additively manufactured object 220 is formed, with the base member 12 placed on a stage 11 . A Z-axis is an axis that is perpendicular to both the X-axis and the Y-axis.

The additive manufacturing apparatus 1 includes the stage 11 on which the workpiece 100 is placed and a stage actuator, which is not shown. The workpiece 100 includes the base member 12 and the additive manufactured object 220 formed on the base member 12 . The base member 12 is placed on the stage 11 . Grains are added to an area of the workpiece 100 referred to as the target addition surface 110 . This in 1 Base element 12 shown is plate-shaped. Instead of the plate shape, the base member 12 may have another shape.

The additive manufacturing apparatus 1 includes a processing head 21 which irradiates a processing site 111 with a laser beam L and melts a thread W which is a process material, and a head actuator 22 which the machining head 21 moves. The processing head 21 comprises a beam output 23, which irradiates the processing site 111 with the laser beam L, two or more thread outputs 31, which each advance the thread W to the processing site 111, and a gas output 41, which outputs a protective gas G to the processing site 111. The processing site 111 is an irradiation position for the laser beam L on the target addition surface 110 and is an area where the process material is added. The machining location 111 is shifted along a machining path while the additive process is being performed.

The beam output 23 emits the laser beam L, a heat source that melts the process material, toward the processing location 111 on the workpiece 100. The energy source that melts the process material can be an electron beam, an arc discharge, or another energy source instead of the laser beam L. Each thread feed-out 31 advances the thread W toward the irradiation position for the laser beam L, which is on the workpiece 100 . In other words, each thread output 31 feeds the thread W to the processing site 111 on the target addition surface 110 of the workpiece 100 .

Instead of feeding the thread W from the thread outlet 31 to the processing site 111, the additive manufacturing apparatus 1 may use a forming method in which metal powder as a process material is discharged from the outlet. In cases where the metal powder is used as the process material, a method of using a negative pressure for the shielding gas G is a method in which for forming, pressurizing the metal powder and discharging the metal powder from a powder feed tube, which the metal powder is transported, used, or another method can be used. In such cases, the discharge that discharges the metal powder is arranged so that the metal powder is discharged in a columnar shape having a center axis corresponding to a center axis of the thread W guided to the processing site 111 . The filament W and the metal powder to be discharged in the columnar shape are both referred to as a process material, which is supplied to the processing site 111 from the discharge in the columnar shape.

The gas discharge 41 discharges the protective gas G, which reduces or prevents oxidation of the additive manufactured object 220 and cools the grains, toward the processing site 111 on the target addition surface 110 . The jet output 23, the thread outputs 31 and the gas output 41 are fixed to the processing head 21 and therefore have a uniquely determined positional relationship. In other words, the relative positions of the jet output 23, the thread outputs 31 and the gas output 41 on the processing head 21 are fixed.

The head actuator 22 moves the machining head 21 in directions, namely, X-axis directions, Y-axis directions, and Z-axis directions. The head actuator 22 includes a servomotor which moves the machining head 21 in the X-axis directions in a moving device, a servomotor which moves the machining head 21 in the Y-axis directions in the moving device, and a servomotor which in the moving device moves moves the machining head 21 in the Z-axis directions. The head actuator 22 is the moving device that enables translations in the directions along the three axes. The servo motors are in 1 not shown. In the additive manufacturing apparatus 1, the head actuator 22 moves the machining head 21, making it possible to shift the irradiation position for the laser beam L on the target addition surface 111. FIG.

the inside 1 The machining head 21 shown causes the laser beam L from the beam output 23 to move in the Z-axis direction. Each yarn output 31 is provided at the position remote from the beam output 23 on the XY plane, and advances the yarn W in a direction oblique to the Z-axis. In other words, the thread W is advanced through the thread outlet 31 without being coaxial with the laser beam L emitted from the beam outlet 23 . The thread output 31 is used to limit the movement of the thread W to feed the thread W to a certain position.

At the machining head 21 , the gas outlet 41 is provided coaxially with the beam outlet 23 around an outer edge of the beam outlet 23 in the XY plane, and discharges the shielding gas G along a central axis of the laser beam L emitted from the beam outlet 23 . In other words, the jet outlet 23 and the gas outlet 41 are arranged coaxially with one another.

Although not shown, the filament output 31 may be coaxial with the jet output 23 . In a conceivable configuration of this case, the thread outlet 31 is arranged in a center, and a gas discharge outlet of the gas outlet 41 and a laser discharge outlet of the beam outlet 23 are arranged in ring shapes centered around the thread W or as a plurality of points which form a center of the thread W surround. In this case, the laser beam L becomes in the form of a ring or plural spots from the beam output 23 emitted and focused on the thread W near the processing location 111.

The device for additive manufacturing 1 further comprises a laser oscillator 24, which emits the oscillating laser beam L, which is to be emitted for irradiation from the beam output 23 of the processing head 21, and a gas supply unit 42, which supplies the gas output 41 of the processing head 21 with the protective gas G. A fiber optic cable 25 is connected between the laser oscillator 24 and the processing head 21 . The laser beam L generated by the laser oscillator 24 is propagated to the beam output 23 via the fiber optic cable 25. A pipe 43 is connected between the gas supply unit 42 and the processing head 21. As shown in FIG. The protective gas G is supplied to the gas outlet 41 from the gas supply unit 42 through the pipe 43 .

The laser oscillator 24, the fiber cable 25 and the beam output 23 form an irradiation unit which irradiates the target addition surface 110 with the laser beam L which melts the filament W and is not coaxial with the central axis of the filament W. The gas supply unit 42, the pipe 43 and the gas outlet 41 form a gas supply device which emits the protective gas G in the direction of the processing site 111.

The additive manufacturing apparatus 1 further includes a filament spool 33 and a rotary motor 34. The filament spool 33 is a process material supply source and has the thread W wound thereon. The rotary motor 34 rotates the thread spool 33. The rotary motor 34 is a servomotor, for example. When the rotation motor 34 is operated, the thread spool 33 is rotated and the thread W is unwound from the thread spool 33 . The thread W unwound from the thread spool 33 passes through the thread outlet 31 to be fed to the processing site 111 . The rotary motor 34, the thread roller 33 and the thread output 31 form a thread feed unit 32.

Because the additive manufacturing apparatus 1 stacks plural kinds of metal in the first embodiment, the additive manufacturing apparatus 1 has plural of the thread feeding units 32. In 1 however, only one of the yarn feed units 32 is shown. An example of a forming method using two kinds of filaments W is given below. In other words, two thread feed units 32 are included in the additive manufacturing device 1 in the given example. In this case, one of the thread feeding units 32 has a first thread output which feeds a first thread made of a first metallic material, and the other thread feeding unit 32 has a second thread output which feeds a second thread made of a second metallic material material is formed. The first metallic material and the second metallic material may be metals composed of a single metallic element or may be alloys composed of multiple metallic compounds. The first and second metallic materials to be selected are a combination of materials that forms an intermetallic compound. For convenience of description, in the first embodiment, the first and second metallic materials have the same thickness.

The device for additive manufacturing 1 includes a rotation device 13 which rotates the object table 11 . The rotating device 13 is a moving device which enables the stage 11 to be rotated around the X-axis and the stage 11 to be rotated around the Z-axis. The rotation can be around the Y axis instead of the X axis. The rotating device 13 comprises a servomotor which in the moving device causes the stage 11 to rotate around the X-axis or the Y-axis, and a servomotor which in the moving device causes the stage 11 to rotate around the Z-axis. The rotation device 13 is the movement device that enables the rotations around the two axes. The servo motors are in 1 Not shown. The additive manufacturing apparatus 1 is capable of changing a posture or a position of the workpiece 100 by rotating the stage 11 with the rotating device 13 . The use of the rotator 13 enables a complex shape to be formed which includes a taper. With the rotation mechanism 13 for the stage 11 and the head actuator 22 described above in combination, the additive manufacturing apparatus 1 is capable of five-axis drive.

The additive manufacturing apparatus 1 includes a control unit 51 which controls the additive manufacturing apparatus 1 according to a processing program. The processing program sets a movement path along which the machining head 21 is to be moved relative to the workpiece 100 placed on the stage 11. FIG.

The control unit 51 controls the laser oscillator 24, the filament feeding units 32 and the gas feeding unit 42, and is responsible for controlling the formation of the plurality of point-like grains formed by fusing the filaments W into the additive manufactured object 220. The control unit 51 is, for example, a numerical control device. When performing drive control The control unit 51 outputs movement commands to the head actuator 22 for moving the processing head 21 to the head actuator 22 . In controlling a laser oscillation of the laser oscillator 24, the controller 51 issues an instruction to the laser oscillator 24 according to a beam power condition.

When performing drive control on the rotary motor 34, the control unit 51 issues an instruction to the rotary motor 34 according to a feed value condition for the yarn W. By performing drive control on the rotary motor 34, the control unit 51 adjusts a speed of the thread W from the thread spool 33 to the irradiation position. In other words, the control unit 51 controls feed values for the threads W of the multiple thread feed units 32.

In controlling a value of shielding gas G to be supplied from the gas supply unit 42 to the gas outlet 41 , the control unit 51 issues an instruction to the gas supplying unit 42 according to a shielding gas G supply value condition. When performing drive control of the rotator 13 , the control unit 51 outputs rotation commands to the rotator 13 . In other words, the control unit 51 controls the entire additive manufacturing apparatus 1 by issuing the various commands.

The control unit 51 is capable of changing the processing location 111 by having the head actuator 22 and the rotator 13 cooperate with each other to move the processing head 21 and the stage 11 so that the additive manufactured object 220 having a desired shape can be obtained .

2 14 is a block diagram showing a first example of a hardware configuration for the control unit of the additive manufacturing apparatus according to the first embodiment. The control unit 51 is implemented using a control program, which is a program for executing the control of the additive manufacturing apparatus 1 .

The control unit 51 includes a central processing unit (CPU) 501 which executes various processes, a random access memory (RAM) 502 which includes a data storage area, a read only memory (ROM) 503 which is a non-volatile memory, an external storage device 504 and a Input/output interface 505 which inputs information to the control unit 51 and outputs information from the control unit 51. In 2 the parts are connected to each other via a bus 506.

The CPU 501 executes programs stored in the ROM 503 and the external storage device 504 . The overall control of the additive manufacturing apparatus 1 by the control unit 51 is implemented using the CPU 501 .

The external storage device 504 is a hard disk drive (HDD) or solid state storage (SSD). The external storage device 504 stores the control program and various data. The ROM 503 stores software or a program that performs hardware control, namely, a program that performs basic control of a computer or controller serving as the control unit 51, such as a BIOS boot loader (Basic Input/Output System ) or a UEFI (Unified Extensible Firmware Interface) bootloader. The control program can be stored in the ROM 503 .

The programs stored in the ROM 503 and the external storage device 504 are loaded into the RAM 502 . The CPU 501 loads the control program into the RAM 502 and executes various processes. The input/output interface 505 is an interface that provides a connection to a device external to the control unit 51 . The processing program is input to the input/output interface 505. The input/output interface 505 issues the various commands. The control unit 51 may include input devices, such as a keyboard and pointing device, and an output device, such as a display.

The control program can be stored in a storage medium readable by the computer. The control unit 51 can store the control program stored in the storage medium into the external storage device 504 . The storage medium can be a portable storage medium, which can be a floppy disk or a flash memory, which can be a semiconductor memory. The control program can be installed on the computer or controller serving as the control unit 51 from another computer or a server device via a communication network.

3 12 is a block diagram showing a second example of the hardware configuration of the control unit of the additive manufacturing apparatus according to the first embodiment. The functions of the control unit 51 can also be implemented by a processing circuit 507, which is shown in 3 dedicated hardware shown. The processing circuit 507 is a single circuit, a composite circuit, a programmed processor, a parallel programmed Processor, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a combination of these. Part of the functions of the control unit 51 can be implemented with dedicated hardware, with another part of the functions being implemented with software or firmware.

The additive manufacturing apparatus 1 forms, on the target addition surface 110 of the base member 12, the additive manufacturing object 220 using the metallic materials by stacking the grains in multiple layers. The grains are of the melted threads W added to the target addition surface 110 of the base member 12 while the machining site 111 is shifted along the machining path. The grains are objects formed by solidification of the melted filaments W, and constitute the additive manufactured object 220.

The additive manufacturing object 220, which can be manufactured with the additive manufacturing apparatus 1 of FIG 1 is obtained. The additive manufacturing apparatus 1 forms the additive manufactured object 220 by stacking the grains; however, there are cases where straight grains are used and cases where point grains are used. The straight grains are hereinafter referred to as line grains, and the point grains are hereinafter referred to as point grains.

4 14 is an enlarged view schematically showing an example of an object formed by line grains. A single line grain 201 is formed by continuously irradiating the processing location 111, which is continuously shifted during the axial movement of the processing head 21, with the laser beam L and continuously advancing the thread W to the processing location 111. By repeating this process, an additive manufactured object 220 consisting of a series of line grains 201 can be obtained. As is clear from the above, the line grain 201 is a straight metal into which the molten filament W has solidified.

5 Fig. 12 is an enlarged view schematically showing an example of an object formed by point grains. A single point grain 211 is formed by making the machining site 111 stand still without the axial movement of the machining head 21 and meanwhile irradiating the laser beam L and feeding the thread W, and thereafter making an axial movement that becomes a size of a single point grain 211 is equivalent. By repeating this process, an additive manufactured object 220 consisting of a series of point grains 211 can be obtained. As is apparent from the above, the point grain 211 is a spherical metal into which the molten filament W has solidified due to surface tension. Compared with the line grain 201, the point grain 211 is formed with a small feed value for the filament W and reduced heat input from the laser beam L, and is therefore small like the single grain. Further, the forming of the point grain 201 does not involve the movement of the machining head 21, resulting in the manufacture of the additive manufactured object 220 with high shape accuracy compared to the formation of the line grain 201, which involves the movement of the machine head 21.

In cases where the thread W to be used has a thickness of about several millimeters, a diameter of the point grain 211, which also depends on a beam diameter of the laser beam L, is about several millimeters when the beam diameter is about several millimeters.

6 14 is a cross-sectional view showing an example configuration of the additive manufactured object according to the first embodiment. 7 14 is a partial perspective view showing the exemplary configuration of the additive manufactured object according to the first embodiment. 8th 14 is a partial cross-sectional view showing the exemplary configuration of the additive manufactured object according to the first embodiment. The 7 and 8th are each an enlarged view of a portion of an area R1 in 6 . In the 6 until 8th a left-right direction on the paper surface is referred to as the X-axis direction, a bottom-up direction is referred to as the Z-axis direction, and a direction belonging to the X-axis direction and the Z-axis -direction is perpendicular is referred to as the Y-axis direction. The Z-axis direction is a stacking direction of the point grains 211.

As in 6 As shown, the additively manufactured object 220 is a stack comprising a first metal layer 230 formed from the first metallic material and a second metal layer 240 formed from the second metallic material. In other words, the additive manufactured object 220 is the object formed by stacking the different types of metal. As in 7 As shown, the first metal layer 230 is a three-dimensional stack of first point grains 231, which are point grains composed of the first metal metallic material, and the second metal layer 240 is a three-dimensional stack of second point grains 241, which are point grains formed of the second metallic material.

The object 220 produced by additive manufacturing according to the first embodiment comprises the first metal layer 230 , the second metal layer 240 and an intermediate layer 250 which is arranged between the first metal layer 230 and the second metal layer 240 . The intermediate layer 250 includes a first structure part 251, which is a structure formed from the first metal material, and a second structure part 252, which is a structure formed from the second metal material. The first structural part 251 and the second structural part 252 interlock in a unitary structure 253 . In a plane perpendicular to the stacking direction of the first metal layer 230 and the second metal layer 240, an arrangement of a plurality of the unit structures 253 arranged in the intermediate layer 250 has translational symmetry, the arrangement being a periodic arrangement. in the in 8th In the example shown, the first structure part 251 is a hook-shaped structure consisting of first point grains 231 protruding from the first metal layer 230 to the second metal layer 240 . The second structure part 252 is a hook-shaped structure consisting of second point grains 241 protruding from the second metal layer 240 to the first metal layer 230 . A hooked configuration of the first structural part 251 and a hooked configuration of the second structural part 252 interlock in the unitary structure 253 . The arrangement of the unit structures 253 has the translational symmetry in the plane perpendicular to the stacking direction of the first metal layer 230 and the second metal layer 240 .

in the in 8th example shown, the hook-shaped configuration of the first structural part 251 comprises two first point grains 231, which are stacked in the Z-axis direction, and a first point grain 231, which is arranged so that it is adjacent to the second metal layer 240 with one of the first point grains 231 , which are stacked in the Z-axis direction, and protrude along the X-axis.

The hooked configuration of the second structural part 252 includes two second point grains 241 stacked in the Z-axis direction and a second point grain 241 arranged to be adjacent to the first metal layer 230 with one of the second point grains 241 which are stacked in the Z-axis direction, connected, and protruding along the X-axis.

The hooked configuration of the first structural member 251 and the hooked configuration of the second structural member 252 are in interlocking engagement, thereby forming the unitary structure 253 . In this example, unit structure 253 has a Y-axis thickness equivalent to a point grain. The unit structures 253 are arranged along the X-axis and the Y-axis, whereby the intermediate layer 250 is formed.

In the 7 and 8th The point grains shown are each as small as about a few millimeters, as described above, and are not so large that when viewing a finished product configuration, the portion of engagement between the first structural part 251 and the second structural part 252 is clearly visible. Therefore, having the engaging parts does not limit a shape and a size of a final product.

Because the arrangement of the unit structures 253 has the translational symmetry at a joint surface between the first metal layer 230 and the second metal layer 240, that is, the engagement parts are uniformly present at the joint surface, the joint surface between the first metal layer 230 and the second metal layer 240 has a uniform bonding strength versus drag directions or the Z-axis directions. The engagement configuration of the first structural part 251 and the second structural part 252, which is shown in 7 and 8th shown is an example and a different engagement configuration may be used. Because the arrangement of the unit structures 253 has the translational symmetry at the interface between the first metal layer 230 and the second metal layer 240 , there are two or more unit structures 253 included in the intermediate layer 250 .

9 14 is a diagram showing an example configuration of the intermediate layer of the additive manufactured object according to the first embodiment. In 9 the first structural parts 251 and the second structural parts 252 of the respective unit structures 253 arranged at positions along the Y-axis are at the same position along the X-axis. In 9 are layers, each comprising an array of point grains, at successive positions along the Y-axis and are shown in spatial relationship. An Nth ply, an (N+1)th ply, and an (N+2)th ply sequential along the Y-axis are shown herein, where N is an integer greater than or equal to zero. As in 9 shown, the first structural parts 251 in the Nth, (N+1)th and (N+2)th layers have the same position along the X-axis, and the second structural parts 252 in the Nth, ( N+1)th and (N+2)th layers have the same position along the X axis. In other words, the N-th layer configurations are sequentially formed along the Y-axis.

Here, a combination of the first structural part 251 and the second structural part 252 positioned at each position along the Y-axis can be construed as the unit structure 253, or a combination of a group of first structural parts 251 formed along the Y-axis and a group of second structure parts 252 formed along the Y-axis can be regarded as the unit structure 253. FIG. In the latter case, the unit structures 253 are arranged along the X-axis, their arrangement exhibiting translational symmetry.

10 14 is a diagram showing another exemplary configuration of the intermediate layer of the additive manufactured object according to the first embodiment. In 10 For example, the first structural parts 251 and the second structural parts 252 arranged along the Y-axis are offset in their positions along the X-axis. While 10 shows the case where the positional displacement along the X-axis per ply displacement in the Y-axis direction is one grain, the positional displacement along the X-axis per predetermined number of the ply displacement in the Y-axis direction may be a predetermined number of be grains. In this case, the unit structure 253 includes an arrangement of a predetermined number of first structure parts 251 along the Y-axis and a predetermined number of second structure parts 252 along the Y-axis.

Next, details of a joint surface portion between the first point grain 231 formed of the first metallic material and the second point grain 241 formed of the second metallic material in the intermediate layer 250 will be described. 11 12 is a diagram schematically showing an example of the joint surface between the first point grain and the second point grain in the additive manufactured object according to the first embodiment. 11 12 is an enlarged schematic view of a portion R2 in FIG 8th . Because the selected first and second metallic materials - as described above - are the materials which form the intermetallic compound, an intermetallic compound layer 255 comprising the intermetallic compound forms at the interface I between the first point grain 231 and the second point grain 241 While the intermetallic compound layer 255 includes the intermetallic compound, the intermetallic compound layer 255 may or may not contain a solid solution and another phase.

Intermetallic compounds are generally known to exhibit unique properties different from those of native metals. The intermetallic compound layer 255 is a third layer having properties different from those of the first and second metallic materials. The intermetallic compound layer 255 formed at the interface I between the first point grain 231 and the second point grain 241 has a role of a barrier layer. The intermetallic compound layer 255 does not have the role of binding the first point grain 231 and the second point grain 241 to each other. In cases where the first and second metallic materials have different coefficients of thermal expansion, the intermetallic compound layer 255 is able to reduce thermal stress resulting from a difference between the coefficients of thermal expansion. In other words, the intermetallic compound layer 255 has a role of a cushioning element.

Because the intermetallic compound layer 255 does not bond the first point grain 231 and the second point grain 241 together, the mere formation of the second point grain 241 on the first point grain 231 does not provide sufficient bonding between the first metal layer 230 and the second metal layer 240. As in 7 until 10 As shown, therefore, in the first embodiment, the first metal layer 230 and the second metal layer 240 are assembled by the engagement between the hook-shaped first structural part 251 and the hook-shaped second structural part 252 of each of the unit structures 253 in the intermediate layer 250 . For this reason, even if the first metal layer 230 and the second metal layer 240 have different coefficients of thermal expansion, bonding between the first metal layer 230 and the second metal layer 240 can be obtained by physically separating the first point grains 231 and the second point grains 241 in the intermediate layer 250 to be ordered.

When the first metal layer 230 and the second metal layer 240 are in contact with each other, a potential difference across the connection surface I causes an electric current to flow, and corrosion is likely to occur. On the other hand, in the first embodiment, the intermetallic compound layer 255 is present between the first point grain 231 and the second point grain 241 . Because many intermetallic compounds do not conduct electricity, the intermetallic compound interrupts the current even when the potential difference between the first metal layer 230 and the second metal layer 240 occurs. Therefore, corrosion occurs with less probability at the connection surface I between the first metal layer 230 and the second metal layer 240 .

12 14 is a diagram showing an example of a state of components at the joint surface between the first point grain and the second point grain in the additive manufactured object according to the first embodiment. In this case, the first metal material is made of a first metal and the second metal material is made of a second metal. Further, the first metal and the second metal are a combination which does not form a solid solution but forms an intermetallic compound. In 12 a horizontal axis represents positions along the Z-axis in the additively manufactured object 220, including the interface I between the first point grains 231 and the second point grains 241, and a vertical axis represents a component amount of the first metal and the second metal. 12 shows how the components, namely the first metal and the second metal, vary in quantity along the Z-axis in a region R3 in 11 change.

The intermetallic compound is a result of combining the first metal and the second metal in a predetermined ratio. As in 12 As shown, therefore, the intermetallic compound layer 255 around the bonding surface I has both the first metal and the second metal as the components in constant amounts. For this reason, whether the intermetallic compound layer 255 is formed at the bonding surface I or not can be easily determined by component analysis using an energy dispersive X-ray spectroscopy system (EDS) or other system equipped with a scanning electron microscope (SEM) or other microscope become.

An example case in which the first metallic material is Fe and the second metallic material is Al will be described. 13 is a phase diagram of Al-Fe. Using Al as a base material and Fe as an added material in a range R4 of 13 provides an intermetallic compound layer 255 comprising only an intermetallic compound or comprising the intermetallic compound and a mixed crystal. In the first embodiment, the intermetallic compound needs to be formed in the intermetallic compound layer 255 regardless of whether the mixed crystal is formed or not. Aluminum with a face-centered cubic structure and Al ₁₂ Fe ₄ form in the region R4 shown.

When forming the second point grain 241 made of Al on the first point grain 231 made of Fe, Fe from a portion defining the first point grain 231 mixes with the molten Al. Thereby, the intermetallic compound is obtained around the joint face I between the first point grain 231 and the second point grain 241 as shown in the region R4 of the phase diagram.

While Al-Fe has been given as the example in the present specification, another combination of a first metallic material and a second metallic material forming an intermetallic compound similarly forms the intermetallic compound at the joint face I between the first point grains 231 and the second point grains 241.

Next, a method of manufacturing the additive manufactured object 220 will be described. 14 until 18 12 are sectional views schematically showing a process example of the method of manufacturing the additive manufactured object according to the first embodiment. As in 14 1, the first point grains 231 formed of the first metal material are first arranged in a desired shape, thereby forming the first metal layer 230. FIG. with the inside 1 Apparatus shown for additive manufacturing 1 is formed by irradiating the processing site 111 with the laser beam L from the beam output 23 a molten pool. In this state, the first thread made of the first metallic material is fed from the thread outlet 31 to the processing site 111 . The processing site 111 is irradiated with the laser beam L so that the first filament is heat-melted to form a first point grain 231 . In this case, the machining head 21 is moved in the Y-axis direction after one first point grain 231 is formed, and then another first point grain 231 is formed. After a row of first dot grains 231 extending in the Y-axis direction is formed, the machining head 21 is moved by a dot grain width in the X-axis direction, and the process of forming a row of first dot grains 231 extending in the Y-axis direction is repeated.

Next, while the supply of the first thread to the processing site 111 and the supply of the second thread to the processing site 111 are switched, the hook-shaped first structural parts 251 and the hook-shaped second structural parts 252 are formed on the first metal layer 230, thereby forming the intermediate layer 250 . In other words, the control unit 51 stops the processing site by no axial movement of the processing head 21 and meanwhile causes the irradiation of the laser beam L and the advancement of the first or second filament to provide between the first metal layer 230 and the second metal layer 240 the arrangement of the unit structures 253 which the translational symmetry in the Has a plane that is perpendicular to the stacking direction of the first metal layer 230 and the second metal layer 240 and that includes the first structure parts 251 and the second structure parts 252 that interlock in the unit structure 253 .

As in 15 1, the second point grain 241 for the second structural part 252 is formed at a predetermined position on the first metal layer 230 specifically. In this forming, a molten pool is formed with the additive manufacturing apparatus 1 by irradiating the processing site 111 with the laser beam L from the beam output 23 . In this state, the second thread formed of the second metal material is fed to the processing site 111 . The processing site 111 is irradiated with the laser beam L so that the second filament is heat-melted to form the second point grain 241 . Second point grains 241 are now formed in succession along the Y-axis in the same way. As in 16 1, the first point grains 231 are each formed by forming a molten pool by irradiating the processing site 111 with the laser beam L from the beam output 23, advancing the first thread to the processing site 111, and then irradiating the processing site 111 with the laser beam L. By repeatedly executing the processes of 15 and 16 becomes the intermediate layer 250 as in 17 shown having the arrangement of the unit structures exhibiting the translational symmetry wherein the hook-shaped first structural member 251 and the hook-shaped second structural member 252 intermesh in the unit structure.

When the second point grain 241 is formed on the first point grain 231, the intermetallic compound layer 255 forms at the interface I between the first point grain 231 and the second point grain 241. When the first point grain 231 is formed on the second point grain 241, the intermetallic compound layer 255 at the connection surface I between the first point grain 231 and the second point grain 241.

As in 18 1, the second point grains 241 are then formed on the intermediate layer 250, whereby the second metal layer 240 is formed. At this time, the second point grains 241 are sequentially formed along the Y-axis in the same manner. This forms the object 220 produced by additive manufacturing, which in 7 and 8th is shown. This completes the process of fabricating the additively manufactured object 220 comprising the first metallic material and the second metallic material.

A difference from a prior art which forms a mixed crystal at an interface between a first point grain 231 and a second point grain 241 will now be described. 19 Fig. 12 is a diagram schematically showing an example of the interface between the first point grain and the second point grain in a prior art additive manufactured object. 19 FIG. 12 is an enlarged schematic view of a part corresponding to the R2 area of FIG 8th is equivalent to. In 19 components that are the same as those in the first embodiment are given the same reference numerals and will not be described. A selected first metal and a selected second metal are materials constituting the mixed crystal, therefore a mixed crystal layer 290 formed of the mixed crystal is formed at the connecting surface I between the first point grain 231 and the second point grain 241, as in FIG 19 is shown.

20 Fig. 12 is a diagram showing an example of a state of components at the connection surface between the first point grain and the second point grain according to the prior art. In this case, the first metal material is made of the first metal and the second metal material is made of the second metal. Further, the first metal and the second metal are a combination that forms the mixed crystal. In 20 a horizontal axis represents positions along the Z-axis in the additively manufactured object 220 that include the interface I between the first point grain 231 and the second point grain 241, and a vertical axis represents a component amount of the first metal and the second metal. 20 shows how the components, namely the first metal and the second metal, vary in quantity along the Z-axis in a range R5 of 19 change.

In the mixed crystal, the original metals show a continuous change in composition. As in 20 1, therefore, the amount of the first metal component increases continuously from an interface between the first point grain 231 and the mixed crystal layer 290 formed at the joint face I between the first point grain 231 and the second point grain 241 to an interface between the mixed crystal layer 290 and the second point grain 241. The amount of the second metal component increases continuously from the interface between the mixed crystal layer 290 and the first point grain 231 to the interface between the mixed crystal layer 290 and the second point grain 241 . Therefore, in the mixed crystal layer 290, at the joining surface I, the slope of the components, namely the first and second metals, is gentle.

With the original metals exhibiting the continuous compositional change, the mixed crystal usually has properties similar to those of the original metals. For this reason, the mixed crystal layer 290 formed of the mixed crystal bonds the first point grain 231 and the second point grain 241 to each other. Therefore, when the first metallic material and the second metallic material have different coefficients of thermal expansion, thermal stress resulting from a difference between the coefficients of thermal expansion causes separation at the mixed crystal layer 290. Where the separation exists are the first point grain 231 and the second point grain 241 are no longer bonded to each other, resulting in the separation between the first metal layer 230 and the second metal layer 240.

Many mixed crystals of first and second metals are electrically conductive. Therefore, when the first metal layer 230 and the second metal layer 240 are in contact through the mixed crystal layer 290, a potential difference across the connection surface I causes an electric current to flow, and corrosion is likely to occur.

The object 220 manufactured by additive manufacturing according to the first embodiment includes the intermediate layer 250 between the first metal layer 230 formed from the first metallic material and the second metal layer 240 formed from the second metallic material. The intermediate layer 250 includes the first structural part 251, which is a hook-shaped structure consisting of the first point grains 231 protruding from the first metal layer 230 to the second metal layer 240, and the second structural part 252, which is the hook-shaped structure consisting of the second point grains 241 protruding from the second metal layer 240 to the first metal layer 230 . The first structural part 251 and the second structural part 252 are interlocked in the unitary structure 253 . The arrangement of the unit structures 253 arranged in the intermediate layer 250 has the translational symmetry in the plane perpendicular to the stacking direction of the first metal layer 230 and the second metal layer 240 . Therefore, compared to a conventional one, the object 220 produced by additive manufacturing does not have any limitation in the combination of the first metal material and the second metal material, and ensures a uniform bonding strength at the joint surface I between the first metal layer 230 and the second metal layer 240 Further, the interlocking between the first structural part 251 and the second structural part 252 in the unitary structure 253 is effected by the physical arrangement of the first and second point grains 231 and 241 and is millimeters in size. Therefore, the unit structure 253 having the interlocking does not limit the shape and size of the final product, enabling the additive manufacturing object 220 to be formed in any shape and size.

The intermetallic compound layer 255 does not bond the first and second point grains 231 and 241 to each other. Even when the coefficients of thermal expansion of the first and second metallic materials are different and cause thermal stress at the junction face I between the first and second point grains 231 and 241, the intermetallic compound layer 255 functions as the thermal stress cushioning member. In addition, when the intermetallic compound layer 255 is not electrically conductive, no electric current flows through the junction area I between the first and second metal layers 230 and 240 even if the potential difference exists due to the contact between the first and second point grains 231 and 241, thereby a progressive corrosion is curbed.

Second embodiment.

In 8th In the first embodiment, there is no difference in thickness between the first metallic material and the second metallic material; however, there are cases where an actual combination of materials has a difference in strength between a first metallic material and a second metallic material. In such cases, a ratio of a number of first point grains 231 to be arranged in the unit structure 253 to a number of second point grains 241 to be arranged in the unit structure 253 is varied according to the thickness between the first and second metallic materials.

It is assumed here that the first metal material has a tensile strength twice that of the second metal material. 21 12 is a partial cross-sectional view showing an exemplary configuration of a through additive manufacturing manufactured object according to a second embodiment. Because the tensile strength of the second metallic material is half the tensile strength of the first metallic material, includes in 21 a Z-axis extending portion of the second structural member 252 in an X-axis direction second point grains 241 twice as many as a first point grain 231 formed in a Z-axis extending portion of the first Structural part 251 is included in an X-axis direction. In this way, a Z-axis tensile strength of the second point grains 241 becomes equal to that of the first point grain 231, and contact loads acting on an interface in directions of tension, namely, along a Z-axis are improved.

Note that this case is an example. The ratio of the number of first point grains 231 of the first structural part 251 to the number of second point grains 241 of the second structural part 252 can be varied according to the strength ratio between the first and second metallic materials.

In the second embodiment, the ratio of the number of first point grains 231 of the first structural part 251 to the number of second point grains 241 of the second structural part 252 varies according to the strength ratio between the first and second metallic materials. This allows a thickness of the bonding surface I between the first metal layer 230 and the second metal layer 240 to remain constant even if point grains of different thicknesses are mixed.

Third embodiment.

In the case described in the second embodiment, when the metallic materials have different strength differences in tensile strength along the one axis, the ratio between the number of point grains in the unit structure 253 is adjusted to solve the strength difference between the metallic materials . In a third embodiment, a configuration of an additive manufactured object 220 is described that can maintain a bond strength at an interface between the first metal layer 230 and the second metal layer 240 even in cases where strengths act in directions other than along one axis .

As in 8th 1, in the first embodiment, the point grain is set on the point grain of the underlying layer to be at the same position as the point grain of the underlying layer along the X-axis and the Y-axis. However, because the point grain is substantially spherical, a packing ratio can be changed freely. 22 14 is a diagram showing an example of how dot grains are arranged in the additive manufactured object according to the third embodiment. 22 shows the case where the point grains are arranged in face-centered cubic lattices. Seen from a Y-axis direction, on an M-th point grain layer composed of point grains, an (M+1)-th point grain layer is formed in a Z-axis direction so that its point grains are each shifted along an X-axis by one are offset by a distance equal to half a grain width, where M is an integer greater than or equal to zero. Similar arrangements are provided across the first metal layer 230, the intermediate layer 250, and the second metal layer 240. FIG. While 22 is a view viewed from the Y-axis direction, the same applies when viewed from an X-axis direction. In this case, the first and second point grains 231 and 241 are arranged such that the face-centered cubic lattice arrangement is maintained also in the intermediate layer 250 and form the hook-shaped first structural parts 251 and the hook-shaped second structural parts 252 . Accordingly, the unit structures 253 are formed in the intermediate layer 250 .

Arranging the point grains in the face-centered cubic lattices in the additively manufactured object 220 increases the point grain packing ratio. In this way, in addition to tension, bond strength can also be improved against loads along multiple axes or in specific directions, as indicated by multiple arrows in FIG 22 is specified, such as bending, shear, compression and torsion.

Instead of being arranged in face-centered cubic lattices, the point grains may be arranged in a close-packed hexagonal lattice structure, a body-centered cubic lattice structure, or some other structure. Therefore, shifting the point grains to be arranged makes it possible to change the strength in any direction. In other words, the additive manufactured object 220 having the strength based on the lattice structure is obtainable.

In general, detachment is likely to occur along a close-packed plane, so the strength at the close-packed plane decreases. If, according to an example, the intermediate layer 250 comprising the unit structure 253 in which the hook-shaped first structural part 251 and the hook-shaped second structural part 252 interlock is provided in a direction that intersects the close-packed plane, at the detachment plane a is increased strength causes.

In the case of the additive manufactured object 220 according to the third embodiment, the point grain is offset relative to the position of the point grain in the underlying point grain layer when placed in the Z-axis direction. For example, the point grains are arranged in face-centered cubic lattices, in body-centered cubic lattices, or close-packed hexagonal lattices. Therefore, the additive manufactured object 220 causes it to have improved strength against a load in one direction attributable to the lattice structure. In other words, an anisotropic adjustment that provides the strength in the specific direction is possible. Further, the meshing between the hook-shaped first structural part 251 and the hook-shaped second structural part 252 can be freely changed by the manner in which the point grains are arranged, making it possible to provide the bonding strength specific to the particular direction.

Fourth embodiment.

In the first to third embodiments, the first metal layer 230 is composed of the first point grains 231. However, the first metal layer 230 need not be composed of the first point grains 231. FIG. In a fourth embodiment, a case where the first metal layer 230 is a plate-shaped member will be described.

23 14 is a cross-sectional view showing an example configuration of an additive manufactured object according to the fourth embodiment. The object 220A produced by additive manufacturing comprises a plate-shaped first metal layer 230A and a second metal layer 240, which are bonded to one another via an intermediate layer 250A. The first metal layer 230A is made of a first metal material, and the second metal layer 240 is made of the second point grains 241 made of a second metal material.

The first metal layer 230A is an element 233 of any shape. The element 233 includes on its target addition surface 110 where the second metal layer 240 is formed, an array of grooves 234 having translational symmetry. The grooves 234 may be grooves 234 that extend along a Y-axis, or may be grooves 234 of predetermined lengths that are spaced at predetermined intervals along the Y-axis. The grooves 234 are also arranged at predetermined intervals along an X-axis. A cross section of each of the grooves 234, which is perpendicular to the Y-axis, which indicates an extending direction of the groove 234, has a shape tapered from a bottom toward an opening. A portion between the X-axis adjacent grooves 234 is referred to as a trapezoidal portion 235 . In one example, a top surface of the trapezoidal portion 235 has an X-axis length equivalent to a point grain size. Since this is exemplary, the X-axis length of the top surface of the trapezoidal portion 235 can be any length as long as desired tensile strengths through a portion between the first metal layer 230A and the second metal layer 240 can be obtained.

Grains 257 formed of the second metallic material are embedded in the grooves 234. As shown in FIG. In other words, the grains 257 bite into the grooves 234. Therefore, in the fourth embodiment, the first structural part 251 corresponds to the groove 234, and the second structural part 252 corresponds to the grain 257. The grain 257 embedded in the groove 234 may be a line grain or point grains include.

Second point grains 241 are disposed on the first metal layer 230A with the grains 257 embedded in the grooves 234. FIG. These second point grains 241 are bonded to grain 257 in groove 234 upon placement. Other second point grains 241 are placed on the trapezoidal part 235 .

The bonding of the grain 257 embedded in the tapered groove 234 and the second point grains 241 prevents the grain 257 engaged in the groove 234 from easily coming out of the groove 234 when a tensile stress along a Z-axis acts, allowing a strong bond between the first metal layer 230A and the second metal layer 240.

In this case, the portion including the groove 234, the grain 257 embedded in the groove 234, and the trapezoidal part 235 form the unit structure 253. A part where an arrangement of the unit structures 235 has translational symmetry is the intermediate layer 250A In cases where the line grain 257 is embedded in the groove 234, a combination of the groove 234 extending along the Y-axis, the grain 257 embedded in the groove 234, and the trapezoidal part 235 is the Unit structure 253, so that the intermediate layer 250 can be thought of as having an X-axis arrangement of the unit structures 253 that has translational symmetry. The intermetallic compound layer 255 is formed at an interface between the first metal layer 230A and the grain 257 as well as at an interface between the first metal layer 230A and the second point grain 241 as described in the first embodiment.

Next, a method of manufacturing such an additive manufactured object 220 will be described. 24 until 30 12 are perspective views schematically showing a process example of the method of manufacturing the additive manufactured object according to the fourth embodiment. As in 24 1, the flat plate-shaped member 233 formed of the first metallic material is first prepared. This flat plate-shaped member 233 becomes the first metal layer 230A. As in 25 1, the grooves 234 extending along the Y-axis are next formed in an upper surface of the first metal layer 230A at the predetermined intervals along the X-axis. The cross-sectional shape of the groove 234, which is perpendicular to the Y-axis, is tapered such that the groove 234 has a smaller area at the opening than at the bottom. According to one example, the grooves 234 are formed by die sinking. Forming the grooves 234 creates the trapezoidal portion 235 between the grooves 234.

As in 26 1, the grains 257 formed of the second metallic material are then embedded in the grooves 234. As shown in FIG. As described above, the grains 257 can be the point grains or the line grains. In this example, grains 257 are the line grains. A portion of the element 233 including the grains 257 embedded in the grooves 234 and the formed trapezoidal parts 235 is the intermediate layer 250A, and a remaining portion of the element 233 is the first metal layer 230A.

As in 27 1, the second point grains 241 formed of the second metallic material are formed on the grain 257 embedded in the groove 234 of the member 233 next. These second point grains 241 are formed as a first row on and along grain 257, which extends along the Y-axis.

As in 28 As shown, on the trapezoidal portion 235 of the element 233 the second point grains 241 are then formed along the Y-axis as a second row which is adjacent to the first row of second point grains 241 along the X-axis. The second row of second point grains 241 is bonded to the first row of second point grains 241 in a molten state.

By repeatedly executing the processes of 27 and 28 a first layer of second point grains 241 is formed on the intermediate layer 250A as in FIG 29 is shown. The same as for the first layer of second point grains 241 is repeated to form a second layer and subsequent layers of second point grains 241 . In this way, the second metal layer 240 is obtained, which is 30 is shown. The element 233 is plate-shaped in the above description, but need not be plate-shaped as long as the element 233 is an element of any shape that is not formed of the first point grains 231 .

In the fourth embodiment, the first metal layer 230</b>A is the element 233 of any shape that is not formed by the first point grains 231 . The grooves 234 each having the cross section of a tapered shape are formed in this first metal layer 230A, and the grains 257 formed of the second metal material are embedded in the grooves 234. FIG. In this way, the intermediate layer 250A is formed. Next, the process of forming a row of second point grains 241 on and along the embedded grain 257 and the process of forming a row of second point grains 241 on the trapezoidal portion 235 in contact with the previously formed row of second point grains 241 are repeated to form the first layer from point grains on the first metal layer 230A. This is repeated to form the second metal layer 240 composed of multiple layers of the second point grains 241 . Because this resultant configuration has the grains 257 engaged with the tapered grooves 234, the same effects as those of the first embodiment can be obtained.

It takes time when the first metal layer 230A is formed from the first point grains 231 because the first point grains 231 are arranged three-dimensionally. However, in the fourth embodiment, the member 233 of any shape is used for the first metal layer 230A, causing the process of preparing the first metal layer 230A to be more efficient compared to the case where the first point grains 231 for assembly are formed individually, a short period of time is required. The intermediate layer 250A is formed by forming the grooves 234 in the member 233 by a method such as die sinking and embedding the grains 257 in the grooves 234. This also enables the process of forming the intermediate layer 250A compared to the case in which the first dot grains 231 and the second dot grains 241 are arranged, a short time is required. Therefore, the manufacturing of the additive manufactured object 220 can be achieved in a shorter time.

The above configurations shown in the embodiments are exemplary, can be used with other known techniques that are publicly available are known can be combined and partially omitted or changed without departing from the concept. The embodiments can be combined with one another.

Reference List

1

additive manufacturing device;

11

object table;

12

base element;

13

rotation device;

21

processing head;

22

head actuator;

23

jet output;

24

laser oscillator;

25

fiber tow;

31

thread output;

32

thread feeding unit;

33

thread spool;

34

rotary engine;

41

gas output;

42

gas supply unit;

43

Pipe;

51

control unit;

100

Workpiece;

110

target addition area;

111

place of processing;

201

line grain;

211

point grain;

220,

220A object manufactured by additive manufacturing;

230,

230A first metal layer;

231

first point grain;

233

Element;

234

groove;

235

trapezoidal part;

240

second metal layer;

241

second point grain;

250, 250A

interlayer;

251

first structural part;

252

second structural part;

253

unit structure;

255

intermetallic compound layer;

257

Grain;

290

mixed crystal layer;

G

protective gas;

I

interface;

L

Laser beam;

W

Thread.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• JP 202041201 [0004]

Claims (8)

An additive manufactured object which is a stack comprising a first metal layer formed from a first metallic material and a second metal layer comprising second point grains formed from a second metallic material, the additive manufactured object includes: an intermediate layer between the first metal layer and the second metal layer, wherein the intermediate layer comprises a first structural part, which is a structure formed from the first metallic material, and a second structural part, which is a structure formed from the second metallic material, the first structural part and the second structural member is interdigitated in each of a plurality of unit structures, wherein an arrangement of the unit structures disposed in the intermediate layer has translational symmetry in a plane perpendicular to a stacking direction of the first metal layer and the second metal layer, wherein the intermediate layer comprises an intermetallic compound layer comprising an intermetallic compound at a junction surface between the first structural part and the second structural part. Object made by additive manufacturing according to claim 1 , wherein the first metal layer comprises first point grains, the first structural part comprises the first point grains arranged such that the first structural part protrudes from the first metal layer to the second metal layer and has a hook-shaped configuration, the second structural part comprises the second point grains, the are arranged such that the second structural member protrudes from the second metal layer toward the first metal layer and has a hooked configuration, and the hooked configuration of the first structural member and the hooked configuration of the second structural member interlock in the unitary structure. Object made by additive manufacturing according to claim 2 , wherein a ratio of a number of the first point grains per unit structure to a number of the second point grains per unit structure varies. Object made by additive manufacturing according to claim 2 or 3 wherein the first point grains and the second point grains that are arranged are each offset relative to a position of a first lower-layer point grain or a position of a second lower-layer point grain. Object made by additive manufacturing according to claim 4 wherein the first point grains and the second point grains are arranged in a face-centered cubic lattice, a centered hexagonal lattice, or a body-centered cubic lattice. Object made by additive manufacturing according to claim 1 wherein the first metal layer is an element of any shape that does not include a first point grain, the first structural part is a groove provided in the first metal layer, and the second structural part is a grain embedded in the groove, the grain being formed of the second metallic material is. A method of fabricating an additive manufactured object that is a stack comprising a first metal layer formed from a first metallic material and a second metal layer comprising second point grains formed from a second metallic material, the method comprising: an intermediate layer forming step of forming an intermediate layer on the first metal layer, the intermediate layer comprising a first structural part which is a structure formed from the first metallic material and a second structural part which is a structure formed from the second metallic material, the first structural member and second structural member are interdigitated in each of a plurality of unit structures, wherein an arrangement of the unit structures disposed in the intermediate layer has translational symmetry in a plane perpendicular to a stacking direction of the first metal layer and the second metal layer; and a second metal layer forming step of arranging the second point grains on the intermediate layer to thereby form the second metal layer, wherein the first metallic material and the second metallic material are a material combination which forms an intermetallic compound layer comprising an intermetallic compound at a connecting surface between the first structural part and the second structural part. An additive manufacturing apparatus comprising: a laser oscillator for emitting an oscillating laser beam; a stage for a workpiece to be placed; a machining head having a beam output for irradiating the workpiece with the laser beam from the laser oscillator, a first filament output for feeding a first filament made of a first metallic material is formed to a processing site which is an irradiation position for the laser beam, and a second filament feed-out for feeding a second filament formed of a second metallic material to the processing site; a head actuator for moving the machining head; and a control unit for controlling the laser oscillator, a feed value for the first thread or the second thread and the head actuator, wherein the control unit stops the machining site by no axis movement of the machining head and in between causes laser beam irradiation and feeding of the first thread or the second thread to between a first metal layer formed of the first metallic material and a second metal layer comprising second point grains formed with the second filament to provide an array of unit structures having translational symmetry in a plane belonging to a stacking direction of the first metal layer and the second metal layer is perpendicular, and in each of the unit structures comprises a first structure part, which is a structure formed of the first metallic material, and a second structure part, which is a structure including the second point grains, which mesh with each other.

Images